593 research outputs found

    Early Embryonic Lethality Caused by Targeted Disruption of the Mouse Thioredoxin Gene

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    AbstractThioredoxins belong to a widely distributed group of small proteins with strong reducing activities mediated by a consensus redox-active dithiol (Cys-Gly-Pro-Cys). Thioredoxin was first isolated as a hydrogen donor for enzymatic synthesis of deoxyribonucleotides by ribonucleotide reductase inEscherichia coli.Recent studies have revealed a variety of roles that thioredoxin plays in transcription, growth control, and immune function. In this report, we describe the phenotype of mice carrying a targeted disruption of the thioredoxin gene (Txn). Heterozygotes are viable, fertile, and appear normal. In contrast, homozygous mutants die shortly after implantation, and the concepti were resorbed prior to gastrulation. When preimplantation embryos were placed in culture, the inner cell mass cells of the homozygous embryos failed to proliferate. These results indicate thatTxnexpression is essential for early differentiation and morphogenesis of the mouse embryo

    Development of a method for measuring rare earth elements in the environment for future experiments with gadolinium-loaded detectors

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    Demand to use gadolinium (Gd) in detectors is increasing in the field of elementary particle physics, especially in neutrino measurements and dark matter searches. Large amounts of Gd are used in these experiments. To assess the impact of Gd on the environment it is becoming important to measure the baseline concentrations of Gd. Such measurement, however, is not easy due to interference by other elements. In this paper a method for measuring the concentrations of rare earth elements, including Gd, is proposed. In the method, inductively coupled plasma-mass spectrometry is utilized after collecting the dissolved elements in chelating resin. Results of the ability to detect anomalous concentrations of rare earth elements in river water samples in the Kamioka and Toyama areas are also reported

    Improved method for measuring low-concentration radium and its application to the Super-Kamiokande Gadolinium project

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    Chemical extraction using a molecular recognition resin named "Empore Radium Rad Disk" was developed to improve sensitivity for the low concentration of radium (Ra). Compared with the previous method, the extraction process speed was improved by a factor of three and the recovery rate for Ra-226 was also improved from 81 +/- 4% to > 99.9%. The sensitivity on the 10(-1) mBq level was achieved using a high-purity germanium detector. This improved method was applied to determine Ra-226 in Gd-2(SO4)(3)center dot 8H(2)O which will be used in the Super-Kamiokande Gadolinium project. The improvement and measurement results are reported in this paper

    Author Correction: CHD3 helicase domain mutations cause a neurodevelopmental syndrome with macrocephaly and impaired speech and language.

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    © 2019, The Author(s). The original version of this Article contained an error in the spelling of the author Laurence Faivre, which was incorrectly given as Laurence Faive. This has now been corrected in both the PDF and HTML versions of the Article

    Single-stranded DNA catenation mediated by human EVL and a type I topoisomerase

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    The human Ena/Vasp-like (EVL) protein is considered to be a bifunctional protein, involved in both actin remodeling and homologous recombination. In the present study, we found that human EVL forms heat-stable multimers of circular single-stranded DNA (ssDNA) molecules in the presence of a type I topoisomerase in vitro. An electron microscopic analysis revealed that the heat-stable ssDNA multimers formed by EVL and topoisomerase were ssDNA catemers. The ssDNA catenation did not occur when either EVL or topoisomerase was omitted from the reaction mixture. A deletion analysis revealed that the ssDNA catenation completely depended on the annealing activity of EVL. Human EVL was captured from a human cell extract by TOPO IIIα-conjugated beads, and the interaction between EVL and TOPO IIIα was confirmed by a surface plasmon resonance analysis. Purified TOPO IIIα catalyzed the ssDNA catenation with EVL as efficiently as the Escherichia coli topoisomerase I. Since the ssDNA cutting and rejoining reactions, which are the sub-steps of ssDNA catenation, may be an essential process in homologous recombination, EVL and TOPO IIIα may function in the processing of DNA intermediates formed during homologous recombination

    Defining forgiveness: Christian clergy and general population perspectives.

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    The lack of any consensual definition of forgiveness is a serious weakness in the research literature (McCullough, Pargament &amp; Thoresen, 2000). As forgiveness is at the core of Christianity, this study returns to the Christian source of the concept to explore the meaning of forgiveness for practicing Christian clergy. Comparisons are made with a general population sample and social science definitions of forgiveness to ensure that a shared meaning of forgiveness is articulated. Anglican and Roman Catholic clergy (N = 209) and a general population sample (N = 159) completed a postal questionnaire about forgiveness. There is agreement on the existence of individual differences in forgiveness. Clergy and the general population perceive reconciliation as necessary for forgiveness while there is no consensus within psychology. The clergy suggests that forgiveness is limitless and that repentance is unnecessary while the general population suggests that there are limits and that repentance is necessary. Psychological definitions do not conceptualize repentance as necessary for forgiveness and the question of limits has not been addressed although within therapy the implicit assumption is that forgiveness is limitless.</p
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